What's the difference between「～と言いました」and「～と言っていました」?

Question

「～と言{い}いました」and「～と言{い}っていました」

basically the difference between します and しています.

Answer 1

You question is more about the difference between ～と言った and ～と言っていた than the difference between します and しています. いう is a special word because all the four forms 言う, 言った, 言っている and 言っていた are used differently.

It seems to me that you will normally use ～と言っている or ～と言っていた to report someone's speech. Perhaps it is helpful to think of them as stative verbs meaning “to think”. The difference is just that ～と言っている suggests the one who said that still thinks so, whereas ～と言っていた is neutral.

What you will find in front of と言っている is often things like requests, commands, feelings, decisions, conclusions, or judgement. Many of them, like たい, ほしい, なさい, しよう, etc., are normally restricted to first or second person subjects. But in Japanese, you can easily extend them to third person subjects by attaching と言っている to the end. In this sense, I think と言っている may not refer to any specific action, but is more related to how one thinks or what one suggests.

On the other hand, と言った usually refers to a specific action in the past. It is perfectly suitable when you are telling a story. I do not know why Japanese generally prefer と言っている over と言った for reporting other people's words. Perhaps it is just because people say something all the time where the focus is not on whether someone has said something or done something, but on what he says.

と言う generally means “people say” or “I heard”. Using と言う instead of と言った is usually seen in novels.

I think verbs like ～と思っている, ～と言っている, ～と考えている all more or less work in this way.

Answer 2

彼は...と言いました states the simple fact as "He said ...", so it fits in academic report or formal letter. 彼は...と言っていました evokes some vividness as "He was saying ...". と言っていました is a more polite expression than と言っていた ( います is more polite than いる ). 言っていた is the past tense of 言っている.